Fix uscan directory check and related fixes

Matthijs Kooijmanrequested to merge
matthijs-guest/devscripts:uscan-fixes into master

This MR was prompted by https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=905866 and partially fixes that bug by making directory name checking (i.e. "--check-dirname-regex") work again, preventing uscan from working on the wrong directory in most cases.

In addition, it fixes some related code I noticed while working on this, and it improves the manpage wrt recursive operation (this one is a bit off-topic, so if you prefer a separate MR for this, let me know).

I also did not include any changelog entries, to prevent conflicts if this not merged right away, but this should be a matter of gbp dch.

Merge request reports